From: James D. Lear <lear@mail.med.upenn.edu>
  To  : Karen G. Fleming <kgf@csb.YALE.EDU>
  Date: Wed, 30 Jul 1997 13:05:54 -0500

Re: interference noise level

I've found that window cleaning is a lot more difficult than one might
expect.  Windows can look clean on casual inspection but be significantly
contaminated with protein films.   Inspection under a very strong light (I
use a focused 10 W microscope illuminator) will often show cloudy
(scattering) areas not apparent in ordinary light.  I use RBS detergent
(Pierce) at about double strength, sometimes with a very, very gentle rub
with a cotton-tipped swab followed by a thorough de-ionized water rinse,
blot-dry with Kimwipes, and storage wrapped in lens paper. Hope this helps.
Jim Lear

James D. Lear
Department of Biochemistry & Biophysics
The Johnson Foundation
School of Medicine
University of Pennsylvania
Philadelphia, PA 19104-6059
(215) 898-2071 (Voice)
(215) 573-7229 OR 898-4217 (FAX)